Analytical design equations for the calculation of the effective width for the analysis of composite steel-concrete bridge decks

This paper proposes new analytical expressions for the determination of effective widths for the analysis of twin-girder steel-concrete composite bridge decks. The main advantage of the proposed approach relies on its ability to evaluate the normal longitudinal stress distribution on the slab by means of a cross sectional analysis carried out using the internal actions calculated by means of a global analysis specifying the real width of the slab along the whole bridge length. The proposed expressions are shown to be able to handle different loading conditions which include constant uniformly distributed loads, envelopes of transverse actions due to traffic loads, support settlements and concrete shrinkage. Comparisons with the methodology recommended by design guidelines are carried to highlight the ease of use and effectiveness of the proposed method considering realistic continuous twin-girder composite bridge decks.